1) love the plot
2) american school system: start school at age 5 or 6 (depends on your birthday) in kindergarten. Elementary school typically goes through 5th grade (so kindergarten, first grade...fifth grade). Some elementary schools include 6th grade, but typically 6-8 is middle school. Then high school is 9-12, you graduate at approximately 18, and go on to college if you wish. Depending on the size of the school in question, the grades may be shuffled a bit between schools (elementary, middle, high). Also, most kids go to 4K or four year old kindergarten before kindergarten, but it is (not yet) a requirement.
3) thanks so much for the story!

One time, I was in chemistry, and my teacher said something about physical changes, like grinding, splitting, smashing...then i got this mental image of the Hulk sitting in piles of rubble going "HULK EXACT PHYSICAL CHANGE!"
No hopes.

This is amazing! I love how much detail and research is put into this, and I love all the family connections that the team has _ It's very bittersweet, and I can't wait for you to update this, because it really is a great storyline that you've created.